COMPUTER NETWORK AND COMMUNICATION.

there are four types of computer network :

1) PAN

A personal area network (PAN) is a computer network used for communication among computer devices (including telephones and personal digital assistants) close to one's person. The devices may or may not belong to the person in question. The reach of a PAN is typically a few meters. PANs can be used for communication among the personal devices themselves (intrapersonal communication), or for connecting to a higher level network and the Internet. Personal area networks may be wired with computer buses such as USB and FireWire.

2) VPN

A virtual private network (VPN) is a network that uses a public telecommunication infrastructure, such as the Internet, to provide remote offices or individual users with secure access to their organization's network. A virtual private network can be contrasted with an expensive system of owned or leased lines that can only be used by one organization. The goal of a VPN is to provide the organization with the same capabilities, but at a much lower cost.

3) WLAN

A wireless LAN (WLAN) is a wireless local area network that links two or more computers or devices using spread-spectrum or OFDM modulation technology based to enable communication between devices in a limited area. This gives users the mobility to move around within a broad coverage area and still be connected to the network.

4) WIMAX

WIMAX, meaning Worldwide Interoperability for Microwave Access, is a telecommunications technology that provides wireless transmission of data using a variety of transmission modes, from point-to-multipoint links to portable and fully mobile internet access. The technology provides up to 3 Mbit/s broadband speed without the need for cables. The technology is based on the IEEE 802.16 standard (also called Broadband Wireless Access). The name "WIMAX" was created by the WIMAX Forum, which was formed in June 2001 to promote conformity and interoperability of the standard. The forum describes WIMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL.

thank for reading :)